/*
 * (c) Copyright 2007, 2008, 2009 Hewlett-Packard Development Company, LP
 * All rights reserved.
 * [See end of file]
 */

package com.hp.hpl.jena.tdb.index.mem;


import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.openjena.atlas.iterator.IteratorConcat ;
import org.openjena.atlas.iterator.NullIterator ;
import org.openjena.atlas.lib.DS ;




import com.hp.hpl.jena.graph.Node;
import com.hp.hpl.jena.graph.Triple;


public class IterFunc
{
    static public Iterator<Triple> noTriples() { return new NullIterator<Triple>() ; }
    
    static public <K1, K2, K3, V> Iterator<V> flatten(Index3<K1, K2, K3, V> idx)
    {
        if ( idx == null )
            return DS.nothing() ;
        return idx.flatten() ;
    }
    
    static public <K1, K2, V> Iterator<V> flatten(Index2<K1, K2, V> idx)
    {
        if ( idx == null )
            return DS.nothing() ;
        return idx.flatten() ;
    }
    
    static public <K1, K2, V> Iterator<V> flattenII(Index<K1, Index<K2, V>> idx)
    {
        if ( idx == null )
            return new ArrayList<V>().iterator() ;
        
        IteratorConcat<V> all = new IteratorConcat<V>() ;
        
        for ( K1 n : idx.keys() )
        {
            Index<K2, V> x = idx.get(n) ;
            all.add(x.values().iterator()) ;
        }
        return all ;
    }

    static public Iterator<Triple> flattenIL(Index<Node, List<Triple>> idx)
    {
        if ( idx == null )
            return DS.nothing() ;
        
        IteratorConcat<Triple> all = new IteratorConcat<Triple>() ;
        
        for ( Node n : idx.keys() )
        {
            List<Triple> x = idx.get(n) ;
            all.add(x.iterator()) ;
        }
        return all ;
    }
}

/*
 * (c) Copyright 2007, 2008, 2009 Hewlett-Packard Development Company, LP
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */